Pathogenicity of Alternaria alternata on fruits and leaves of 'Fortune' mandarin (Citrus clementina × Citrus tangerina)

• Published in: Canadian journal of plant pathology Vol. 34; no. 2; pp. 195 - 202
• Main Authors: Nemsa, I., Hernández, M. A., Lacasa, A., Porras, I., García-Lidón, A., Cifuentes, D., Bouzid, S., Ortuño, A., Del Río, J. A.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 01.04.2012; Taylor & Francis Ltd
• Subjects: 'Fortune' mandarin; Alternaria alternata; Alternaria brown spot; Black rot; Citrus; Fruits; Growth stage; Infection; Inoculation; ITS rDNA; Leaves; Mandarine Fortune; Maturity; Nucleotide sequence; Orchards; Pathogenicity; Pathogens; pathogénicité; Spacer; tache noire
• ISSN: 0706-0661; 1715-2992
• DOI: 10.1080/07060661.2012.676570

Nine isolates of Alternaria causing black rot of 'Fortune' mandarin were obtained from a commercial orchard in the Murcia region of south-east Spain. The isolates, according to their morphological and physiological characteristics, were identified as A. alternata. Analysis of DNA sequences of the internal transcribed spacers 1 (ITS1) and 2 (ITS2) of the ribosomal DNA corroborated the morphological identification. In this work, we evaluated the pathogenicity of each of the nine isolates on fruits and leaves as well as fruit susceptibility to the pathogen at different growth stages. Studies were performed on both wounded and unwounded fruits and leaves. Disease development was faster in wounded than in unwounded organs, one and two days after inoculation, respectively. Differences in pathogenicity were observed among the A. alternata isolates, depending on the plant organ. Immature fruits were more susceptible; fruit infection tolerance increased with maturity, for both wounded and unwounded fruits. These findings could contribute to more-successful phytosanitary management of the disease.